The present invention relates to a new and distinct cultivar of Rose, species Rosa, and further known by the varietal name ‘Pejamblu.’ This new variety is also sold under the Breeder's reference name PEJAMBLU. The new variety was discovered through selective cross-pollination initiated in June 2000. The seed parent is known as “Rose ‘NATURAL BEAUTY’ (ROGSCRIV)”, a pink/apricot colored rose having double 26-40 petals of a 75 mm rosette borne on small clusters. No patent is known by the inventor to cover the parental seed. The pollen parent seedling was derived from a cross of SUMMER WINE and SCRIVBELL. PEJAMBLU has a unique mauve/lilac flower ageing to slate blue, with semi-double 12-16 petals and 75-100 mm flowers. The derivation by cross pollination occurred at 324 City Road, Tividale, Oldbury, West Midlands, United Kingdom B691QP. The first asexual reproduction occurred at the breeder Peter James' home at 324 City Road, Tividale B691QP, Oldbury West Midlands, U.K. Plants were budded on to Lasca under stock and proved to be true to type when grown over several generations and all have been stable. Propagation by cuttings in Australia has also proved stable, and the desirable features of the plant have remained constant throughout the evaluation period. The evaluation of the variety was carried out at Warner Roses of Shropshire. U.K. TF109EP.